Virus-Induced T Cell-Mediated Heterologous Immunity and Vaccine Development

• Published in: Frontiers in immunology Vol. 11; p. 513
• Main Authors: Balz, Kathrin, Trassl, Lilith, Härtel, Valerie, Nelson, Philipp P., Skevaki, Chrysanthi
• Format: Journal Article
• Language: English
• Published: Switzerland Frontiers Media S.A 31.03.2020
• Subjects: Animals; Cross Reactions - immunology; cross-protection; Humans; immune memory; Immunity, Cellular - immunology; Immunity, Heterologous - immunology; Immunology; molecular mimicry; T cell epitope; T-Lymphocytes - immunology; TCR repertoire; Viral Vaccines - immunology; Virus Diseases - immunology; virus-induced immunity; immunomodulation; molecular mimicry; immunopathology; immune memory; virus-induced immunity; T cell epitope; TCR repertoire; cross-protection
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2020.00513

Heterologous immunity (H.I.) is a consequence of an encounter with a specific antigen, which can alter the subsequent immune response to a different antigen. This can happen at the innate immune system level-often called trained immunity or innate immune memory-and/or at the adaptive immune system level involving T memory cells and antibodies. Viruses may also induce T cell-mediated H.I., which can confer protection or drive immunopathology against other virus subtypes, related or unrelated viruses, other pathogens, auto- or allo-antigens. It is important to understand the underlying mechanisms for the development of antiviral "universal" vaccines and broader T cell responses rather than just subtype-specific antibody responses as in the case of influenza. Furthermore, knowledge about determinants of vaccine-mediated H.I. may inform public health policies and provide suggestions for repurposing existing vaccines. Here, we introduce H.I. and provide an overview of evidence on virus- and antiviral vaccine-induced T cell-mediated cross-reactive responses. We also discuss the factors influencing final clinical outcome of virus-mediated H.I. as well as non-specific beneficial effects of live attenuated antiviral vaccines such as measles and vaccinia. Available epidemiological and mechanistic data have implications both for the development of new vaccines and for personalized vaccinology, which are presented. Finally, we formulate future research priorities and opportunities.